What Causes Standing Waves and Beat Frequencies in Sound?

[penza]

Which one of the following situations could result in a standing wave?
A- Two waves with different frequencies moving in the same direction.
B- Two waves with different frequencies moving in opposite direction.
C- Two identical waves moving in opposite directions
D- Two identical waves moving in the same direction.

Two sound waves of frequencies 250.0 Hz and 250.1 Hz are generated. To determine the beat frequency an observer must wait at least
A- 0.004S
B-0.1S
C- 1S
D-10S

 

[berkeman]

-1- What is the most common way that standing waves are generated?

-2- What is the frequency of the beat? What does that tell you about how long it takes you to detect that beat frequency?

 

[penza]

-1- What is the most common way that standing waves are generated?

-2- What is the frequency of the beat? What does that tell you about how long it takes you to detect that beat frequency?

the most common way i don't know...and the frequency of beat is 1/F

 

[Hootenanny]

(1) What is a stading wave? How would you define it?

(2) No the beat frequency is given by the difference in frequency of the two waves thus; f_beat = |f₂ - f₁| . This can be derived from the wave equations of the two interfering waves. Do you know what causes the beating? If not I suggest you look at http://hyperphysics.phy-astr.gsu.edu/hbase/sound/beat.html"

Edit: Sorry berkeman if I stepped on your toes, but you were 'offline'